Why can't you cancel it? Is there some kind of error that the app shows you? Maybe you just need to increase gas price. You can check this web site to see how much gas is recommended (if you are not in a hurry, you can use Gas Price SafeLow (Gwei)).
Thank you
I will chuck this and try
Just remember. If you have any incentives earned, you must first claim it and then cancel the staking. Otherwise you'll loose the tokens you earned trough staking.
Also, Etherscan.io currently doesn't show value in USD of the new HAT tokens. So if you see USD value of the HAT tokens in your wallet, then it's the old tokens and you must swap it.